text: Clifford Nass, the Stanford University sociologist who helped pioneer studies that undermined ideas about multitasking, has died at age 55. The man who dedicated his career to thinking about how humans live in a digital age died after taking part in a hike near Lake Tahoe Saturday. At Stanford, Nass was "a larger than life character," his colleague professor Byron Reeves tells NPR's All Things Considered. Reeves says Nass "was just incredibly enthusiastic about his work, about students." As for Nass' legacy, Reeves says his colleague worked to trace how technology has moved "from tools to social actors," in which everything from robots and computer-laden cars can now use interactive software to present visual cues. "These were essentially social responses," Reeves says. "And humans were built for those kinds of social responses, and to recognize that kind of social interaction and to participate... and they did." A graduate of Princeton University with degrees in mathematics and sociology, Nass worked as a computer scientist at Intel Corp. before beginning his work at Stanford, according to the Stanford Report. The school paper adds, "He was also a professional magician." Nass's work on multitasking was just one part of how he examined the way people interact with technology. He also wrote books about voice recognition software, and the ways people think about computers and television. But it was his research — and his skepticism — about multitasking that drew the most notice. And Nass didn't have to look far for test subjects. "The top 25 percent of Stanford students are using four or more media at one time whenever they're using media," he told NPR's Science Friday this past May. "So when they're writing a paper, they're also Facebooking, listening to music, texting, Twittering, et cetera. And that's something that just couldn't happen in previous generations even if we wanted it to." To anyone who claims they're able to multitask, to concentrate on multiple things at once while still thinking creatively and using their memory, Nass had a ready response. "They're basically terrible at all sorts of cognitive tasks, including multitasking," he told Science Friday's Ira Flatow, citing a raft of scientific research. In Nass's view, people who say they're good at multitasking because they do it all the time are like smokers who say they've always smoked — so it can't be bad form them. "People who multitask all the time can't filter out irrelevancy. They can't manage a working memory. They're chronically distracted," Nass said. "They initiate much larger parts of their brain that are irrelevant to the task at hand. And even - they're even terrible at multitasking. When we ask them to multitask, they're actually worse at it. So they're pretty much mental wrecks." Nass also warned that the mental strain of taking in an ever-increasing load of information through electronic media hasn't been fully realized. "Companies now create policies that force their employees to multitask," he said, according to the Stanford Report. "It's an OSHA (Occupational Safety and Health Administration) problem. It's not safe for people's brains." Another of Nass' experiments revolved around how people see virtual versions of themselves — particularly when given the option of giving themselves feedback. Here's how he explained the results of a study during a 2010 appearance on NPR:  "We've done studies, for example, in which... you take a test on a computer and the feedback is either given not only by your own voice but your own face, saying you did a good job or you did a bad job, or someone else has. "And people not only thought they did better when they got feedback from their own voice, they thought their own face and voice was more intelligent, more likable, and in fact they remembered more of the positive and fewer of the negative comments."